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PHOME 213390
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PROJECT PERIODIC REPORT
Grant Agreement number: 213390
Project acronym: PHOME
Project title: Photonic Metamaterials
Funding Scheme:
□
Periodic report:
1st
Period covered:
from
2nd
□
3rd
June 1, 2010
□x
4th
□
to August 31, 2011
Name, title and organisation of the scientific representative of the project's coordinator1:
Costas M. Soukoulis, Professor, IESL-FORTH, Heraklion, Crete, Greece
Tel: +30 2810 391303 & +30 2810 391547
E-mail: [email protected]
Project website2 address: http://esperia.iesl.forth.gr/~ppm/PHOME/
1
Usually the contact person of the coordinator as specified in Art. 8.1. of the grant agreement
The home page of the website should contain the generic European flag and the FP7 logo which are available in
electronic format at the Europa website (logo of the European flag: http://europa.eu/abc/symbols/emblem/index_en.htm
; logo of the 7th FP: http://ec.europa.eu/research/fp7/index_en.cfm?pg=logos). The area of activity of the project should
also be mentioned.
2
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Declaration by the scientific representative of the project coordinator1
I, as scientific representative of the coordinator1 of this project and in line with the obligations
as stated in Article II.2.3 of the Grant Agreement declare that:

The attached periodic report represents an accurate description of the work carried out in
this project for this reporting period;

The project (tick as appropriate):
x□ has fully achieved its objectives and technical goals for the period;
□ has achieved most of its3 objectives and technical goals for the
period with
relatively minor deviations ;
□ has failed to achieve critical objectives and/or is not at all on schedule4.

The public website is up to date, if applicable.

To my best knowledge, the financial statements which are being submitted as part of this
report are in line with the actual work carried out and are consistent with the report on
the resources used for the project (section 3.6) and if applicable with the certificate on
financial statement.

All beneficiaries, in particular non-profit public bodies, secondary and higher education
establishments, research organisations and SMEs, have declared to have verified their
legal status. Any changes have been reported under section 5 (Project Management) in
accordance with Article II.3.f of the Grant Agreement.
Name of scientific representative of the Coordinator1: Costas M. Soukoulis................................
Date: ............10/ .....June/ 2010............
Signature of scientific representative of the Coordinator1: ...
3
4
If either of these boxes is ticked, the report should reflect these and any remedial actions taken.
If either of these boxes is ticked, the report should reflect these and any remedial actions taken.
....................
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Declaration by the scientific representative of the project coordinator1 .............................................. 2
Publishable summary ....................................................................................................................... 3
1. Project objectives for the period ............................................................................................... 4
2. Work progress and achievements during the period ................................................................. 5
3. Deliverables and milestones tables ......................................................................................... 19
4. Project management ................................................................................................................ 20
5. Explanation of the use of the resources .................................................................................. 21
6. Appendices .............................................................................................................................. 24
Publishable summary
The field of electromagnetic metamaterials is driven by fascinating and far-reaching theoretical
visions such as, e.g., perfect lenses, invisibility cloaking, and enhanced nonlinearities. This
emerging field has seen spectacular experimental progress in recent years. Yet, two major challenge
remains: (i) realizing truly low-loss metamaterial structures. Linear gain inclusion in lossy
metamaterials may provide a solution. (ii) Realizing true 3D metamaterial structures that will give
negative n in different directions. Direct laser writing (DLW) may provide the solution of 3D
isotropic metamaterials.
In the theory/modeling domain (WP1) we developed/improved various modeling tools: we
extended the Finite Difference Time Domain (FDTD) code to lossy and to dispersive materials, we
developed an inversion of the scattering data procedure, which enables to extract effective
parameters (ε and μ) from the transmission data for chiral metamaterials, and we pursued the
Microwave Studio, and FEMLAB commercial software, which gives the ability to treat very thin
metals. In addition, we set out to take a systematic approach towards self-consistent calculations
(using the semi-classical theory of lasing) for realistic gain materials that can be incorporated into
or close to the NIMs, to reduce the losses at THz and optical frequencies. We developed, implement
and used our own FDTD code to treat the field propagation and non-linear response of the gain
material by coupling a set of auxiliary equations for the polarization oscillators and rate equations to
the source-free Maxwell equations. Using FDTD simulations we studied the compensation of
spatially distributed loss of metamaterials by differently spatially distributed inclusions of nonlinear gain for 2D model systems.
A lot of simulations were made, with aim to find new 3D interconnected designs that can be
fabricated by directed laser writing by our experimental partners. We have new blueprints for bulk
connected photonic metamaterials and new chiral metamaterials that give negative index of
refraction. Our experimental partners have fabricated and characterized chiral metamaterials at
GHz, THz and telecom wavelengths. Finally, using transformation optics, various plasmonic
structures have been designed and studied analytically, whereas, until now, only the numerical tool
was available for the study of such plasmonic devices. Novel physical insights have been provided
regards the resonant behavior of these nanostructures and the nanofocusing properties that can be
expected with nanoparticle dimers. These nanostructures exhibit considerable nanofocusing
capabilities: our theory predicts a field enhancement that can go beyond a factor of 104 over a
broadband spectrum.
On the fabrication domain (WP2), as proposed, we have fabricated planar and non-planar new
chiral metamaterials that give negative n at GHz frequencies. We have fabricated chiral
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metamaterials at THz frequencies and telecom wavelengths (1.5 micron). The telecom design is
composed of pairs of twisted gold crosses using two successive electron-beam-lithography steps
with intermediate planarization via a spin-on-dielectrics. We have fabricated a bulk photonic
metamaterial with direct laser writing (DLW). DLW can be viewed as a 3D analogue of electronbeam lithography. Fabrication of polymer structures by this approach is standard. Infilling or
coating of such polymer structures with metals is not standard at all. We have pursued chemical
vapor deposition of silver and also infilling with gold with electroplating, and we were successful in
both these two techniques. Coating approaches using chemical vapor deposition have successfully
been developed. More recently, infilling with gold using an electroplating approach has turned out
to be highly attractive. This work can be viewed as a possible first “real-world” application of the
far-reaching concepts of electromagnetic metamaterials.
On the characterization and testing task (WP3): We performed a large number of free space
transmission measurements in the 10 GHz, and 30 GHz regimes, using all our 1D and 2D
fabricating structures, with both planar and non-planar chiral metamaterials. In the experiment, HP
8364B network analyzer with two Narda standard horn antennas measures the transmission
coefficient. Four linear transmission coefficients, Txx, Tyx, Txy, and Tyy, are measured and the
circular transmission coefficients, T+ +, T− +, T+ −, and T− − are converted from the linear transmission
coefficients. Using the standard definitions of the polarization azimuth rotation,  =[arg(T+
+)−arg(T− −)) /2, and the ellipticity,  = 0.5 arcsin{(|T+ +|−|T− −|)/(|T+ +|+|T− −|)}, of elliptically
polarized light, we calculate the polarization changes in a linearly polarized wave incident on the
cross-wire structures. We have used the numerically develop a retrieval procedure adopting the
uniaxial bianisotropic model to calculate the effective parameters, ,  and n- and n+, of the chiral
metamaterial design. We prove the existence of the negative index originating from the chirality 
of the cross-wire metamaterial. As a comparison, the non-chiral version of the cross-wires pair
design does not show any negative refractive index. We have optically characterized the chiral
structures in the visible and near infrared and in the mid-infrared with circularly polarized incident
light. Our measurements did not produce negative n at these high frequencies, but the strong optical
rotation exists. Finally, we have fabricated and measured by THz spectroscopy the dynamic
response of metamaterials, which give blue shift tenability and broadband tenability.
As promised, we created a web page for our consortium. The URL site is
http://esperia.iesl.forth.gr/~ppm/PHOME/
1. Project objectives for the period
The photonic metamaterials (PHOME) project has three scientific work packages (WP) and two
extra ones, which are not scientific.
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WP1 deals with the modeling and the theory of photonic metamaterials (PMMs). Leader:
FORTH
 WP2 deals with the fabrication of photonic metamaterials (GHz to THz). Leader: Bilkent
 WP3 deals with optical characterization and testing of photonic metamaterials. Leader: KIT
 WP4 deals with the dissemination of the photonic metamaterials results. Leader: Imperial
 WP5 deals with project management. Leader: FORTH
The objectives or tasks of the three work packages for the reporting period are the following:
PHOME 213390
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Objective: T1.1 Design of 3D connected PMMs and the extraction of the effective
parameters  and n.
Objective: T1.2 Software and method development to model 3D chiral metallic
nanostructures.
Objective: T1.3 Self-consistent calculations of incorporating gain and non-linearity in
PMMs. Reduction of losses.
Objective: T1.4 Blueprints for thin-film isolators, for electro-optic modulators and optical
switching.
Objective: T2.1 Optimization of chemical-vapor-deposition (CVD) apparatus for metal
coating of 3D templates from the inside.
Objective: T2.2 Conversion of theoretical blueprints from WP1 into 3D polymer structures
that can actually be made via direct laser writing and CVD coating. Test of the designs in
larger structures, operating at GHz range.
Objective: T2.3 Optimization of successive electron-beam lithography, electron-beam
evaporation, and planarization processes specifically for the novel materials and substrates
involved.
Objective: T3.2 Linear optical characterization of all PMMs made in WP2 and parameter
retrieval.
Objective: T3.3 Experiments on frequency conversion from tailored structures designed in
WP1 and fabricated in WP2).
Objective: T3.4 Luminescence experiments on emitters embedded in or in the vicinity of
PMMs under low (modified spontaneous emission) and high (gain) optical pumping
2. Work progress and achievements during the period
We have all the pdf files of our published and submitted papers in our web site
(http://esperia.iesl.forth.gr/~ppm/PHOME/) and one can find all the details of these results.
During the second year (June 1, 2010 to August 31, 2011) we have done an excellent job in
accomplishing all the objectives for the reporting period (June 1, 2010 to August 31, 2011). In
summary we describe what we have accomplished in the following three WPs:
Theory and Simulation
1. Development of the retrieval procedure for chiral metamaterials to extract the effective
parameters ( and n) with and without substrate.
2. Find new designs for planar and non-planar chiral metamaterials that give an alternative root for
negative index of refraction, and give strong optical activity.
3. We have demonstrated for the first time, theoretically and numerically, that the Casimir force
can be repulsive by using chiral metamaterials.
4. Losses in metamaterials render the applications of such exotic materials less practical unless an
efficient way of reducing them is found. We present two different techniques to reduce ohmic
losses at both lower and higher frequencies, based on geometric tailoring of the individual
magnetic constituents. We show that an increased radius of curvature, in general, leads to the
least losses in metamaterials. Particularly at higher THz frequencies, bulky structures
outperform the planar structures.
5. We have developed a self-consistent method to treat active materials in dispersive media as
metamaterials. This method can help understand if introducing gain materials in metamaterials
can reduce the losses. We are working to implement this method to work for 3D structures.
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6. We have also presented new bulk designs that possess negative index of refraction at telecom
frequencies and are easy to fabricate with direct laser writing, which is the most promising
technique for the fabrication of truly 3D large scale optical metamaterials.
7. Using transformation optics, various plasmonic structures have been designed and studied
analytically, whereas, until now, only the numerical tool was available for the study of such
plasmonic devices. These nanostructures exhibit considerable nanofocusing capabilities: our
theory predicts a field enhancement that can go beyond a factor of 104 over a broadband
spectrum.
8. Radiation losses have been investigated both numerically and analytically in these devices. A
good robustness relative to radiation losses has been predicted for structure dimension up to 400
nm. Nanostructures like a cylinder with a crescent-shaped cross-section or kissing cylinders are
powerful light harvesting devices over a broadband spectrum, both in the visible and near
infrared spectra.
Fabrication
1. A negative index of refraction due to three-dimensional chirality is demonstrated for a bilayered
metamaterial based on pairs of mutually twisted planar metal patterns in parallel planes, which
also shows negative electric and magnetic responses and exceptionally strong optical activity
and circular dichroism.
2. Following our recent theoretical suggestion and microwave experiments, the UniKarl group has
fabricated photonic metamaterials composed of pairs of twisted gold crosses and 4-U’s
structures using two successive electron-beam-lithography steps and intermediate planarization
via a spin-on dielectric.
3. Demonstration of a nonlinear photonic metamaterial by adding a nonlinear material (GaAs) to a
split-ring-resonator array.
4. Fabricate structures that will be used for dynamic response of metamaterials at THz regime.
They produce blueshift tenability and broadband simulation.
5. Direct laser writing (DLW) can be viewed as the three-dimensional analogue of electron-beam
lithography. Fabrication of polymer structures by this approach is standard. In fact, we are using
a commercial instrument from Nanoscribe GmbH (a collaboration with Carl Zeiss) that has
emerged out of previous Karlsruhe work. Infilling or coating of such polymer structures with
metals is not standard at all. We have pursued chemical-vapor deposition of silver and silver
shadow evaporation. We have fabricated 2D metamaterials structures.
6. First realization of a three-dimensional gold-helix photonic metamaterial via direct laser writing
into a positive-tone photoresist and subsequent infilling with gold via electroplating.
7. Finally, reaching beyond the original goals of PHOME first 3D invisibility cloaking structures
have been realized – another striking demonstration of the future possibilities of our direct laser
writing approach for making 3D metamaterials at optical frequencies.
Measurements
Free space transmission measurements of 1D and 2D chiral structures, at GHz frequencies,
discovery of strong optical activity and negative refraction.
2. We have fabricated twisted-cross photonic metamaterials that exhibit strong and pure optical
activity in a fairly large spectra range around 1.3 micron wavelength. In addition, we have used
a different design (4-U’s) and exhibit strong activity at 3 micron wavelength.
3. Transmission properties of the bilayered form of the metamaterial for left-handed (LCP) and
right-handed (RCP) circular polarizations. The structure shows exceptionally strong circular
dichroism and strong rotation angle. Pure optical activity, i.e., polarization azimuth rotation
1.
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without any change of ellipticity, is achieved between resonances, where the absolute rotation is
about 800° per wavelength (6 GHz) and about 400° per wavelength (105 THz) for 4-U’s and
about 60° per wavelength (220 THz) for crosee wires.
We have fabricated many split-ring resonator (SRR) structures on crystalline GaAs
semiconductor substrates. We find strong coupling between the electromagnetic near-fields of
the split rings and the underlying GaAs substrate, resulting in measured second-harmonic
generation (SHG) that is about 25 times stronger than that we have previously found for splitring-resonator arrays on glass substrate.
Such strong interaction between the SRRs and the underlying semiconductor is also crucial for
compensating metamaterial losses by introducing gain. In our corresponding design studies, we
have considered SRR on top of a thin gain layer. We using electron-beam lithography have also
fabricated many corresponding structures. Various gain layers are available to us from
cooperation partner, i.e., single quantum wells, three quantum wells, layers of quantum dots, or
thin bulk films. A dedicated low-temperature femtosecond pump/probe experiment has been
assembled. In this setup, pulses centered around 800-nm wavelength derived from a Ti:sapphire
laser are used as the optical pump. Average powers around 100 mW focused to spots on the
sample with diameters around 20-30 µm enable extremely strong pumping conditions, for which
quantum well (QW) gain is expected. Fortunately, under these intense, essentially continuouswave, pumping conditions, no sample deterioration has been observed. The probe pulses are
derived from an optical parametric oscillator (OPO) that is tunable at around 1500-nm
wavelength. The setup allows for detecting pump-induced changes in transmittance. The
samples are cooled in a He-flow cryostat to increase the anticipated material gain. However,
under conditions of intense pumping and at low temperatures, we have so far not found any
“SPASING” action, which would be a clear-cut proof of complete compensation of
metamaterial losses by the gain.
THz time-domain spectroscopy is used to probe the electromagnetic properties of
metamaterials, that were fabricated within the PHOME, which are dynamically photo excited,
using synchronized femtosecond near-infrared laser pulses. Blushift tunability of the
metamaterials and a broadband phase tenability at about 45°. These results cab be used as a
switching effect at THz frequencies.
We have fabricated and demonstrated metamaterials based enhanced transmission through subwavelength apertures.
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WP1: Theory and Modeling
 A summary of progress towards objectives and details for each task
Work package 1 (WP1) is devoted to new design concepts and their simulations; these designs shall
lead, among other goals, to optimized low-loss, broad bandwidth PMMs to be fabricated in WP2
and characterized in WP3. Development of new software and methods to model 3D chiral
metamaterials will be also part of the WP1 efforts. In addition, we will also develop a selfconsistent theory of incorporating gain or nonlinearity in PMMs. We have developed the 2D code
for incorporating gain in metamaterials. We are working to implement the 3D code, which needs a
lot of computer memory. Furthermore, blueprints for 3D metamaterials have been developed that
acknowledge the conceptual boundary conditions of the novel corresponding fabrication approaches
pursued in WP2. We have addressed all the four tasks T1.1 (Design of 3D connected PMMs and
the extraction of the effective parameters ( and n), T1.2 (Software and method development to
model 3D chiral metallic nanostructures), T1.3 (Self-consistent calculations of incorporating gain
and non-linearity in PMMs. Reduction of losses), and T1.4 (Blueprints for thin-film isolators, for
electro-optic modulators and optical switching) and we have substantial progress in the second year.
We have followed the traditional way to reduce losses by eliminating the sharp corners, and also by
geometric tailoring we found ways to reduce the losses. In addition, our Imperial partners have
pursue another way to use transformation optics to design and study analytically novel plasmonic
metamaterials structures showing nanofocusing abilities, (for details see the second year report).
 Highlight clearly significant results
 First self-consistent calculation of 3D metamaterials with gain (PRB 2010, ref. 25; Opt.
Expr. 2010, ref. 7; Opt. Expr. 2011, ref. 28; Phot. & Nanostr. 2011, ref. 31).
 Design of planar and non-planar chiral metmaterials that give negative n and strong optical
activity (Opt. Lett. 2010, ref. 1; Opt. Lett. 2010, ref. 6; APL 2010, ref. 22; Opt. Expr. 2010,
ref. 24; Opt. Expr. 2011, ref. 34).
 Design of intra-connected 3D isotropic bulk negative index photonic metamaterial (Science
2010, ref. 10; Nature Photonics 2011 ref. 20).
 Reducing losses in photonic metamaterials (Science 2010, ref. 10; Nature Photonics 2011
ref. 20).
 Design of Electromagnetic Induced Transparency (EIT) to reduce the speed of light and
losses (APL 2010, ref. 26; PRL 201, ref. 29).
 Based on conformal transformation, a general strategy is proposed to design plasmonic
capable of an efficient harvesting of light over a broadband spectrum (Nano Letters, 2010,
ref. 59).
 The physics of the interaction between plasmonic nanoparticles has been revisited with
transformation optics. Novel physical insights have been provided regards the resonant
behavior of these nanostructures and the nanofocusing properties that can be expected with
nanoparticle dimers. We use 2D wedge-like structures, tapered wave guides, open
nanocrescents or overlapping cylinders than can be able to exhibit a singularity, which may
give rise to a divergence of the electric field, even in presence of dissipation losses. This
singular behavior had not been pointed out in the past and can be of great interest for single
molecule detection. (ACS Nano 2011, ref. 51; PRB 2011, ref. 52; ACS Nano 2011, ref. 53;
PRB 2010, ref. 55; Nano Lett. 2010, ref. 56; New J. Phys. 2010, ref. 57; PRB 2010, ref. 58).
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WP2: Fabrication of photonic metamaterials
 A summary of progress towards objectives and details for each task
Work package 2 (WP2) is devoted to a systematic study of materials and processing methods to
optimize the quality of micro- and nanofabricated PMMs. Furthermore; novel fabrication
approaches shall be explored for 3D structures. The latter idea is very risky, but it is worth
pursuing, especially in the spirit of the FET program, which supports exploitation of ideas that can
open new possibilities and set new trends for feature research. As PMMs are scaled to higher
frequencies, the quality of materials and fabrication becomes of increasing importance. Because
PMMs are based on resonant micro and nanostructured conductors, fabrication tolerance and
surface quality are crucial. Our team brings extraordinary fabrication capabilities, with access to
nearly all state-of-the-art fabrication facilities, including electron- and focused-ion-beam (FIB)
lithography, as well as direct laser writing for true 3D structures. During the first two years, we
have performed a careful study of the various figures-of-merit of NIM prototypes as a function of
fabrication conditions, including material deposition conditions, annealing and surface smoothness,
and quality as characterized by atomic-force microscopy. We have addressed the three tasks of
WP2, T2.1 (Optimization of chemical-vapor-deposition (CVD) apparatus for metal coating of 3D
templates from the inside), T2.2 (Conversion of theoretical blueprints from WP1 into 3D polymer
structures that can actually be made via direct laser writing and CVD coating. Test of the designs in
larger structures, operating at GHz range), and T2.3 (Optimization of successive electron-beam
lithography, electron-beam evaporation, and planarization processes specifically for the novel
materials and substrates involved).
In detail, as proposed, we have pursued two alternative and complementary fabrication approaches
for three-dimensional (3D), i.e., non-planar, photonic metamaterials: (i) Direct laser writing and (ii)
stacking of layers made via electron-beam lithography. While we have considered the novel
approach (i) as very risky at the time of the proposal, it has delivered several results already and
even unexpected variations of this approach are emerging from KIT.
 Highlight clearly significant results
 First realization of a three-dimensional gold-helix photonic metamaterial as broadband
circular polarizer (Physics Today 2010, ref. 5, Science 2010, ref. 10; Nature Photonics 2011,
ref. 20).
 Demonstration of a photonic 3D photonic metamaterial made via 3D direct laser writing
(Opt. Matt. Expr. 2011, ref. 18; Nature Photonics 2011, ref. 20).
 First demonstration of 3D invisibility cloak at optical wavelengths made via 3D direct laser
writing (Physics Today 2010, ref. 5; Opt. Expr. 10, ref. 8; Opt. Lett. 2011, ref. 13; Opt.
Expr. 2011, ref. 14; Opt. Expr. 2010, ref. 3).
 Fabrications of planar chiral metamaterials that give negative n and strong optical activity at
THz frequencies (Opt. Lett. 2011, ref. 1; Nature Photonics 2011, ref. 20).
 Dynamic response of metamaterials in the THz regime: Broadband blue-shift switch (PRL.
2011, ref. 27).
 Design and fabricated a planar metamaterial that exhibits Electromagnetic Induced
Transparency (EIT) at around 10 GHz with metals and superconductors (APL 2010, ref. 26;
PRL 201, ref. 29).
 Demonstration of a nonlinear photonic metamaterial by adding a nonlinear material (GaAs)
to a split-ring-resonator array (Opt. Expr. 2010, ref. 7).
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 Metamaterials based enhanced transmission through sub-wavelength apertures (J. of
Nanophotonics 2011, ref. 45; J. of Appl. Phys. 2011, ref. 35; Opt. Expr. 2010, ref. 38; Phys.
Stat. Solidi 2010, ref. 39; Opt. Lett. 2011, ref. 47 ).
 Design and fabricated metamaterials absorbers (Opt. Expr. 2011, ref. 30; J. of Appl. Phys.
2010, ref. 38; IEEE 2011, ref. 48).
WP3: Optical characterization and testing
 A summary of progress towards objectives and details for each task
Work package 3 (WP3) is devoted to the characterization of the metamaterial structures made in
WP2. The fabrication in WP2 is obviously intimately interwoven with the optical characterization
and testing in WP3. Thus below, the significant results are the same as in WP2. This requires
innovative approaches regarding the retrieval of optical constants from experimentally accessible
parameters. The experiments include THz time-domain spectroscopy, optical transmittance and
reflectance spectroscopy, laser based interferometry, near-field optical spectroscopy, as well as
nonlinear optical spectroscopy. These measurements will be accompanied by thorough theoretical
analysis and modeling emerging from WP1. With the combined efforts of Work packages 1-3,
photonic metamaterials could make the step from sub-wavelength thickness films towards truly 3D
materials. If this risky enterprise is successful, the step to ICT relevant devices and demonstrators is
small. Examples are “poor man’s” optical isolators, optical switching, and electro-optic modulators.
During the first two years, we have address all the tasks of WP3, T3.1 (Optical characterization of
all PMMs made in WP2), T3.2 (Linear optical characterization of all PMMs made in WP2 and
parameter retrieval), T3.3 (Experiments on frequency conversion from tailored structures designed
in WP1 and fabricated in WP2), T3.4 (Luminescence experiments on emitters embedded in or in
the vicinity of PMMs under low (modified spontaneous emission) and high (gain) optical pumping).
Much of the optical metamaterial characterization performed by KIT in this project is not standard
at all. This comprises the following set-ups:
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Quantitative optical spectroscopy on individual metamaterial elements (“photonic atoms”).
We have put much effort into further optimizing data quality as well as into reducing
measurement times by replacing the pervious mechanical translation stages by
piezoelelectric actuators along all thee spatial axes. This step has allowed extensive studies
on “photonic molecules” of SRR (made via electron-beam lithography) in which we have
systematically investigated the effects of SRR distance and orientation. As outlined above,
this work is important for avoiding break-up effects in metamaterials incorporating optical
gain.
Optical spectroscopy with circularly polarized incident light in the visible and nearinfrared. Our corresponding home-built set-up has been further improved, now also
allowing for analysis of the state of polarization emerging from the metamaterial sample.
Optical spectroscopy with circularly polarized incident light in the mid-infrared. As
described in the proposal, we are operating two commercial Fourier-transform microscopyspectrometers allowing for spectroscopy on small samples up to wavelengths of about 10
µm. These instruments did not allow for circular polarization of the incident light at all –
which, however, is crucial for characterizing three-dimensional chiral metamaterial
structures. Thus, we have custom modified these instruments: A home-made compact holder
encompasses a linear CaF2 “High Extinction Ratio” holographic polarizer and a super-
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achromatic quarter-wave plate that can be rotated from the outside of the microscope. The
custom-made MgF2 based super-achromatic quarter-wave plate (Bernhard Halle Nachfl.)
has a phase error below only ± 14 % in the entire spectral range from 2.5 to 7.0 µm
wavelength of light. This modification allows for conveniently adjusting left and righthanded circular polarization of the incident light. Furthermore, we have modified the
reflective ×36 Cassegrain optics with NA=0.5 by introducing a small diaphragm such that
the full opening angle of the light incident onto the sample is reduced to about 5 degrees. By
tilting the sample we achieve actual normal incidence of light onto the sample.
A dedicated low-temperature femtosecond pump/probe experiment has been assembled. In
this setup, pulses centred around 800-nm wavelength derived from a Ti:sapphire laser are
used as the optical pump. Average powers around 100 mW focused to spots on the sample
with diameters around 20-30 µm enable extremely strong pumping conditions, for which
quantum well (QW) gain is expected. Fortunately, under these intense, essentially
continuous-wave, pumping conditions, no sample deterioration has been observed. The
probe pulses are derived from an optical parametric oscillator (OPO) that is tunable at
around 1500-nm wavelength. The setup allows for detecting pump-induced changes in
transmittance. The samples are cooled in a He-flow cryostat to increase the anticipated
material gain. This set up will be used to see if we can compensate the losses by gain
material.
 Highlight clearly significant results
 First realization of a three-dimensional gold-helix photonic metamaterial as broadband
circular polarizer (Physics Today 2010, ref. 5, Science 2010, ref. 10; Nature Photonics 2011,
ref. 20).
 Demonstration of a photonic 3D photonic metamaterial made via 3D direct laser writing
(Opt. Matt. Expr. 2011, ref. 18; Nature Photonics 2011, ref. 20).
 First demonstration of 3D invisibility cloak at optical wavelengths made via 3D direct laser
writing (Physics Today 2010, ref. 5; Opt. Expr. 10, ref. 8; Opt. Lett. 2011, ref. 13; Opt.
Expr. 2011, ref. 14; Opt. Expr. 2010, ref. 3).
 Fabrications of planar chiral metamaterials that give negative n and strong optical activity at
THz frequencies (Opt. Lett. 2011, ref. 1; Nature Photonics 2011, ref. 20).
 Dynamic response of metamaterials in the THz regime: Broadband blue-shift switch (PRL.
2011, ref. 27).
 Design and fabricated a planar metamaterial that exhibits Electromagnetic Induced
Transparency (EIT) at around 10 GHz with metals and superconductors (APL 2010, ref. 26;
PRL 201, ref. 29).
 Demonstration of a nonlinear photonic metamaterial by adding a nonlinear material (GaAs)
to a split-ring-resonator array (Opt. Expr. 2010, ref. 7).
 Metamaterials based enhanced transmission through sub-wavelength apertures (J. of
Nanophotonics 2011, ref. 45; J. of Appl. Phys. 2011, ref. 35; Opt. Expr. 2010, ref. 38; Phys.
Stat. Solidi 2010, ref. 39; Opt. Lett. 2011, ref. 47 ).
 Design and fabricated metamaterials absorbers (Opt. Expr. 2011, ref. 30; J. of Appl. Phys.
2010, ref. 38; IEEE 2011, ref. 48).
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WP4: Dissemination of the photonic metamaterials results
In the current reporting period we had a large number of publications and invited talks at
conferences and institutions, where we advertised the PHOME results. Below we mention some
steps, planned or done, towards dissemination and use of the PHOME results..
 We have created a web page where we plan to put our articles on PMMs and our main
results. This page is linked to the CORDIS sites, it gives links to the main groups working
on the area of metamaterials and it will be connected also to the main metamaterial related
web pages in the near future.
 We present and we will continue to present the PHOME results through publications,
colloquia, and participations to conferences and workshops.
 We have organized sessions devoted to PMMs at international conferences (SPIE 2010, San
Diego, USA, August 2010; Metamaterials Congress Conference, Karlsruhe, Germany
September 2010; International Workshop on Photonic and Electromagnetic Crystal
Structures, (PECS-IX), Granada, Spain, September 2010; Medi-Nano 3, Belgrade, Serbia,
October 2010; 3nd International Workshop on Theoretical and Computational
Nanophotonics (TaCoNa-Photonics), Bad Honnef, Germany, December 2010; The 3rd
European Topical Meeting on Nanophotonics and Metamaterials, NanoMeta-2011, Seefeld,
Tirol, Austria, January 2011; 41st Winter Colloquium on the Physics of Quantum
Electronics (PQE), Snowbird (U.S.A.), January 2011; SPIE Photonics Europe 2011,
“Metamaterials” Prague, Czech Republic, April 2011; International Conference on Materials
for Advanced Technologies (ICMAT 2011), Singapore, June 2011; SPIE 2011, San Diego,
USA, August 2011), where PHOME results will be advertised.
 We have organized a conference on Photonic Metamaterials at Rethymnon, Crete, Greece,
in June 2011. In this conference new results were presented and were discussed what are the
challenges and the future of the photonic metamaterials. See the website
http://cmp.physics.iastate.edu/wavepro/ and all the talks are posted in this site.
 We have organized a European school devoted to “Experimental characterization of
electromagnetic metamaterials”, Heraklion, Crete, December 13-17 2010, where many
young researchers had the chance to familiarize themselves with the field of photonic
metamaterials.
 The experimental group of Karlsruhe is in discussion with industries about potential
applications of PMMs as optical isolators.
 We plan to send any information (high level publication, appearances of FET projects etc.)
to the DG Information Society
Below we list publications and the invited talks and seminars on photonic metamaterials, which
took place during the current reporting period. The publications are listed also at the project
webpage, at http://esperia.iesl.forth.gr/~ppm/PHOME/
Puclications:
1. M. Decker, R. Zhao, C.M. Soukoulis, S. Linden, and M. Wegener, Twisted split-ring-resonator photonic
metamaterial with huge optical activity, Opt. Lett. 35, 1593 (2010).
2. M. Burresi, D. Diessel, D. van Osten, S. Linden, M. Wegener, and L. Kuipers, Phase-sensitive near-field
optical microscopy on negative-index metamaterials, Nano Lett. 10, 2480 (2010).
3. T. Ergin, J.C. Halimeh, N. Stenger, and M. Wegener, Optical microscopy of 3D carpet cloaks: raytracing simulations, Opt. Express 18, 20535 (2010).
PHOME 213390
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4. L. Shao, M. Ruther, S. Linden, S. Essig, K. Busch, J. Weissmüller, and M. Wegener, Electrochemical
Modulation of Photonic Metamaterials, Adv. Mater. 22, 5173 (2010).
5. M. Wegener and S. Linden, Shaping Optical Space with Metamaterials, Physics Today 63, 32 (2010).
6. D. Diessel, M. Decker, S. Linden, and M. Wegener, Near-field optical experiments on low-symmetry
split-ring-resonator arrays, Opt. Lett. 35, 3661 (2010).
7. N. Meinzer, M. Ruther, S. Linden, C.M. Soukoulis, G. Khitrova, J. Hendrickson, J.D. Olitzky, H.M.
Gibbs, and M. Wegener, Arrays of Ag split-ring resonators coupled to InGaAs single-quantum-well
gain, Opt. Express 18, 24140 (2010).
8. R. Schmied, J.C. Halimeh, and M. Wegener, Conformal carpet and grating cloaks, Opt. Express 18,
24361 (2010).
9. G. Boudarham, N. Feth, V. Myroshnychenko, S. Linden, O. Stephan, C. Colliex, J. Garcia de Abajo, M.
Wegener, and M. Kociak, Spectral Imaging of Individual Split-Ring Resonators, Phys. Rev. Lett. 105,
255501 (2010).
10. C.M. Soukoulis and M. Wegener, Optical Metamaterials: More Bulky and Less Lossy, Science 330,
1633 (2010).
11. M. Ruther, L. Shao, S. Linden, J. Weissmüller, and M. Wegener, Electrochemical Restructuring of
Plasmonic Metamaterials, Appl. Phys. Lett. 98, 013112 (2011).
12. F.B.P. Niesler, N. Feth, S. Linden, and M. Wegener, Second-harmonic optical spectroscopy on splitring-resonator arrays, Opt. Lett. 36, 1533 (2011).
13. J. Fischer, T. Ergin, and M. Wegener, Three-dimensional polarization-independent visible-frequency
carpet invisibility cloak, Opt. Lett. 36, 2059 (2011).
14. J.C. Halimeh, R. Schmied, and M. Wegener, Newtonian photorealistic ray tracing of grating cloaks and
correlation-function-based cloaking-quality assessment, Opt. Express 19, 6078 (2011).
15. M. Decker, N. Feth, C.M. Soukoulis, S. Linden, and M. Wegener, Retarded long-range interaction in
split-ring-resonator square arrays, Phys. Rev. B 84, 085416 (2011).
16. J. Müller, T. Ergin, N. Stenger, and M. Wegener, Doppelt sehen oder gar nicht sehen, Physik Journal 3,
16 (2011).
17. M.J. Huttunen, G. Bautista, M. Decker, S. Linden, M. Wegener, and M. Kauranen, Nonlinear chiral
imaging of subwavelength-sized twisted-cross gold nanodimers, Opt. Mater. Express 1, 46 (2011).
18. J. Fischer and M. Wegener, Three-dimensional direct laser writing inspired by stimulated-emissiondepletion microscopy, Opt. Mater. Express 1, 614 (2011).
19. T.J.A. Wolf, J. Fischer, M. Wegener, and A.-N. Unterreiner, Pump-probe spectroscopy on
photoinitiators for stimulated-emission-depletion optical lithography, Opt. Lett., in press (2011).
20. C.M. Soukoulis and M. Wegener, Past achievements and future challenges in the development of threedimensional photonic metamaterials, Nature Photon., (Published online 17 July 2011).
21. A. Frölich and M. Wegener, Spectroscopic characterization of highly doped ZnO by atomic-layer
deposition for three-dimensional infrared metamaterials, Opt. Mater. Express, in press (2011).
22. Z. Li, R. Zhao, Th. Koschny, M. Kafesaki, E. Colak, H. Caglayan, E. Ozbay and C. M. Soukoulis,
“Chiral metamaterials with negative refractive index based on Four-U-SRRs resonators,” Appl. Phys.
Lett. 97, 081901 (2010).
23. R. S. Penciu, M. Kafesaki, Th. Koschny, E. N. Economou and C. M. Soukoulis, “Magnetic response of
nanoscale left-handed metamaterials,” Phys. Rev. B 81, 235111 (2010).
24. R. Zhao, Th. Koschny and C. M. Soukoulis, “Chiral memamaterials: Retrieval of the effective
parameters with and without substrate,” Opt. Express 18, 14553 (2010).
25. A. Fang, Th. Koschny, and C. M. Soukoulis, “Self-consistent calculations of loss compensated fishnet
metamaterials,” Phys. Rev. B 82, 121102 (R) (2010).
26. Lei Zhang, P. Tassin, Th. Koschny, C. Kurter, S. M. Anlage and C. M. Soukoulis, “Large group delay in
a microwave metamaterial analog of Electromagnetic Induced Transparency,” Appl. Phys. Lett. 97,
241904 (2010).
27. N. H. Shen, M. Massaouti, M. Gokkavas, J. M. Manceau, E. Ozbay, S. Tzortzakis, M. Kafesaki, and C.
M. Soukoulis, “Optical implemented broadband blue-shift switch in the terahertz regime,” Phys. Rev.
Lett. 106, 037403 (2011).
28. A. Fang, Z. Huang Th. Koschny, and C. M. Soukoulis, “Overcoming losses of a split ring resonator array
with gain,” Opt. Express 19, 12688 (2011).
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29. C. Kurter, P. Tassin, Lei Zhang, Th. Koschny, A. P. Zhuravel, A. V. Ustinov, S. M. Anlage and C. M.
Soukoulis, “Classical analogue of Electromagnetic Induced Transparency with a metal/superconductor
hybrid metamaterial,” Phys. Rev. Lett. 107, 043901 (2011).
30. K. B. Alici, A. B. Turhan, C. M. Soukoulis, and E. Ozbay, “Optically thin composite resonant absorber
at the near-infrared band: a polarization independent and spectrally broadband configuration,” Opt.
Express 19, 14260 (2011).
31. A. Fang, Z. Huang Th. Koschny, and C. M. Soukoulis, “Loss compensated negative index materials at
optical wavelengths,” Photonics and Nanostructures 9, xxxx (2011).
32. H. Caglayan and Ekmel Ozbay, “Observation of cavity structures in composite metamaterials,” Journal
of Nanophotonics 4, 041790 (2010).
33. Ekmel Ozbay, “Photonic Metamaterials: Science Meets Magic,” IEEE Photonics Journal 2, 249 (2010).
34. E. Saenz, K. Guven, E. Ozbay, I. Ederra, and R. Gonzalo, “Decoupling of Multifrequency Dipole
Antenna Arrays for Microwave Imaging Applications,” Inter. Journal of Antennas and Propagation,
Appl. Phys. 2010, 843624 (2010).
35. E. Colak, A. O. Cakmak, A. E. Serebryannikov, and E. Ozbay, “Spatial filtering using dielectric
photonic crystals at beam-type excitation," J. Appl. Phys. 108, 113106 (2010).
36. A. E. Serebryannikov, P.V. Usik, and E. Ozbay, “Defect-mode-like transmission and localization of light
in photonic crystals without defects,” Phys. Rev. B 82, 165131 (2010).
37. K. B. Alici, F. Bilotti, L. Vegni, and E. Ozbay, “Experimental verification of metamaterial based
subwavelength microwave absorbers,” J of Appl. Phys. 108, 083113 (2010).
38. A. O. Cakmak, E. Colak, A. E. Serebryannikov, and E. Ozbay, "Unidirectional transmission in photoniccrystal gratings at beam-type illumination," Optics Express 18, 22283 (2010).
39. K. B. Alici, and E. Ozbay, “Metamaterial inspired enhanced far-field transmission through a
subwavelength nano-hole,” Physica Status Solidi RRL 4, 286 (2010).
40. H. Caglayan, S. Cakmakyapan, S. A. Addae, M. A. Pinard, D. Caliskan, K. Aslan, and Ekmel Ozbay,
“Ultrafast and and sensitive bioassay using SRR structures and microwave heating” Appl. Phys. Lett. 97,
093701 (2010).
41. S. Cakmakyapan, A. E. Serebryannikov, H. Caglayan, and Ekmel Ozbay, "One-way transmission
through the subwavelength slit in nonsymmetric metallic gratings," Optics Letters 35, 2597 (2010).
42. K. B. Alici, A. E. Serebryannikov, and E. Ozbay, "Radiation properties and coupling analysis of a
metamaterial based, dual polarization, dual band, multiple split ring resonator antenna," J. of
Electromagn. Waves and Appl. 24, 1183 (2010).
43. A. E. Serebryannikov, and Ekmel Ozbay “Non-ideal multifrequency cloaking using strongly dispersive
materials,” Physica B 405, 2959 (2010).
44. M. Mutlu, A. E. Akosman, A. E. Serebryannikov, and Ekmel Ozbay, "Asymmetric transmission of
linearly polarized waves and polarization angle dependent wave rotation using a chiral metamaterial,"
Optics Express 19, 14290 (2011).
45. L. Sahin, K. Aydin, G. T. Sayan and Ekmel Ozbay, “Enhanced transmission of electromagnetic waves
through split-ring resonator-shaped apertures,” J. of Nanophotonics 5, 051812 (2011).
46. M. Mutlu, A. E. Akosman, A. E. Serebryannikov, and Ekmel Ozbay, “Asymmetric chiral metamaterial
circular polarizer based on four U-shaped split ring resonators,” Optics Letters 36, 1653 (2011).
47. Zhaofeng Li, K. B. Alici, E. Colak, and Ekmel Ozbay, “Complementary chiral metamaterials with giant
optical activity and negative refractive index,” Appl. Phys. Lett. 98, 161907 (2011).
48. F. Bilotti, A. Toscano, K. B. Alici, Ekmel Ozbay, and L. Vegni “Design of Miniaturized Narrowband
Absorbers Based on Resonant-Magnetic Inclusions,” IEEE Transactions on Electromagnetic
Compatibility 53, 63 (2011).
49. K. B. Alici, A. E. Serebryannikov, and Ekmel Ozbay “Photonic magnetic metamaterial basics,”
Photonics and Nanostructures 7, 15 (2011).
50. S. Cakmakyapan, H. Caglayan, A. E. Serebryannikov, and E. Ozbay, "Experimental validation of strong
directional selectivity in nonsymmetric metallic gratings with a subwavelength slit," Appl. Phys. Lett. 98,
051103 (2011).
51. A. Aubry, D. A. Lei, S. A. Maier, and J. B. Pendry, “Plasmonic Hybridization between Nanowires and a
Metallic Surface: A Transformation Optics Approach,” ACS NANO 5, 3293 (2011).
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52. Yu Luo, A. Aubry, and J. B. Pendry, “Electromagnetic contribution to surface-enhanced Raman
scattering from rough metal surfaces: A transformation optics approach,” Phys. Rev. B 83, 155422
(2011).
53. Dang Yuan Lei, A. Aubry, Yu Luo, S. A. Maier and J. B. Pendry. “Plasmonic Interaction between
Overlapping Nanowires,” ACS NANO 5, 597 (2011).
54. A. Aubry, Dang Yuan Lei, S. A. Maier and J. B. Pendry. “Interaction between Plasmonic Nanoparticles
Revisited with Transformation Optics,” Phys. Rev. Lett. 105, 233901 (2010).
55. A. Aubry, Dang Yuan Lei, Stefan A. Maier, and J. B. Pendry, “Conformal transformation applied to
plasmonics beyond the quasistatic limit,” Phys. Rev. B 82, 205109 (2010).
56. Yu Luo, J. B. Pendry and A. Aubry, “Surface Plasmons and Singularities,” Nano Letters 10 4186 (2010).
57. Dang Yuan Lei, A. Aubry, S. A Maier and J. B Pendry “Broadband nano-focusing of light using kissing
nanowires,” New J. of Phys. 12, 093030 (2010).
58. A. Aubry, Dang Yuan Lei, Stefan A. Maier, and J. B. Pendry, “Broadband plasmonic device
concentrating the energy at the nanoscale: The crescent-shaped cylinder,” Phys. Rev. B 82, 125430
(2010).
59. A. Aubry, Dang Yuan Lei, A. I. Fernandez-Domínguez, Y. Sonnefraud, S. A. Maier and J. B. Pendry
“Plasmonic Light-Harvesting Devices over the Whole Visible Spectrum,” Nano Letters 10 2574 (2010).
Conference presentations (only Invited Talks listed here)
1. M. Kafesaki, ”5th Forum on New Materials in CIMTEC 2010 Conference,” Florence, Italy, June 2010
2. M. Kafesaki, ”12th International Conference on Transparent Optical Networks (ICTON),” Munich,
Germany, June 2010.
3. M. Kafesaki, “Summer school on ”Mesoscopic Physics in Complex Media”, Cargese, Corsica, July 2010.
4. M. Kafesaki, “SPIE Optics and Photonics conference on “Nanoscienc+Engineering”, San Diego, USA,
August 2010.
5. M. Kafesaki, “Metamaterials 2010”, Karlsruhe, Germany, September 2010.
6. M. Kafesaki, ”3rd Mediterranean Conference on Nanophotonics,” (Medi-Nano 3), Belgrade, Serbia,
October 2010.
7. M. Kafesaki, "International Workshop on Theoretical and Computational Nanophotonics 2010"
(TaCoNa-Photonics2010), Bad Honnef, Germany, November 3-5, 2011.
8. M. Kafesaki, "Progress In Electromagnetics Research Symposium 2011" (PIERS 2011), Marrakesh,
Morocco, March 20-23, 2011.
9. M. Kafesaki, Annual international conference "Days of Diffraction" (Metamaterials Workshop), St.
Petersburg, Russia, May 30 - June 3, 2011.
10. M. Kafesaki, International Symposium on Wave Propagation: From Electrons to Photonic Crystals and
Metamaterials, Crete, Greece, June 8-11, 2011.
11. M. Kafesaki, International Conference on Materials for Advanced Technologies (ICMAT 2011),
Singapore, June 26 – July 1, 2011.
12. M. Kafesaki, "Moscow International Symposium on Magnetism" (MISM), Moscow, Russia, August 21 –
25, 2011.
13. C.M. Soukoulis, SPIE Optics and Photonics, San Diego, Ca, USA, August 1-6, 2010 (Plenary Talk).
14. C. M. Soukoulis, International Conference on Electromagnetic Metamaterials IV: New Directions in
Active and Passive Metamaterials, Santa Ana Pueblo, New Mexico, August 11-12, 2010.
15. C. M. Soukoulis, Fourth International Congress on Advanced Electromagnetic Materials in Microwaves
and Optics (Metamaterials 2010), Karlsruhe, Germany, September 12-16, 2010.
16. C. M. Soukoulis, Metamaterials Doctoral School, Bringing Gain to Metamaterials, Karlsruhe, Germany,
September 17-18, 2010 (Tutorial).
17. C. M. Soukoulis, International Workshop on Photonic and Electromagnetic Crystal Structures, (PECSIX), Granada, Spain, September 26-30, 2010.
18. C. M. Soukoulis, International Symposium on Wave Propagation: From Electrons to Photonic Crystals
and Metamaterials, Crete, Greece, June 8-11, 2011.
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19. C. M. Soukoulis, International Conference on Materials for Advanced Technologies (ICMAT 2011),
Singapore, June 26 – July 1, 2011.
20. C.M. Soukoulis, SPIE Optics and Photonics, San Diego, Ca, USA, August 21-25, 2011.
21. M. Wegener, Photonic metamaterials and transformation optics, iNANO International summer school in
advanced photonics, Fuglsocenter (Denmark), September 3-7, 2010.
22. N. Stenger, T. Ergin, J.C. Halimeh, and M. Wegener, 3D Optical Carpet Cloak, Fourth International
Congress on Advanced Electromagnetic Materials in Microwaves and Optics Metamaterials 2010,
Karlsruhe (Germany), September 13-16, 2010.
23. S. Linden, N. Feth, M. Decker, M. König, J. Niegemann, K. Busch, and M. Wegener, Electromagnetic
interaction of split-ring resonators: The role of separation and relative orientation, Fourth International
Congress on Advanced Electromagnetic Materials in Microwaves and Optics Metamaterials 2010,
Karlsruhe (Germany), September 13-16, 2010.
24. M. Wegener, Photonic Metamaterials: Recent Progress, PECS IX – The 9th International Photonic &
Electromagnetic Crystal Structures Meeting, Granada (Spain), September 26-30, 2010.
25. M. Wegener, Photonic Metamaterials, “Micro-Optics” Meeting, European Optical Society Annual
Meeting, Paris (France), October 26-28, 2010.
26. N. Meinzer, M. Ruther, S. Linden, C.M. Soukoulis, G. Khitrova, J. Hendrickson, J.D. Olitzky, H.M.
Gibbs, and M. Wegener, Plasmonic Metamaterials Coupled to Single-Quantum-Well Gain, 41st Winter
Colloquium on the Physics of Quantum Electronics (PQE), Snowbird (U.S.A.), January 2-6, 2011.
27. M. Wegener, 3D Metamaterials and Transformation Optics, The 3rd International Topical Meeting on
Nanophotonics and Metamaterials, NANOMETA 2011, Seefeld (Austria), January 3-6, 2011.
28. M. Wegener, Three-dimensional diffraction-unlimited direct-laser-writing optical lithography,
International Workshop “Laser Based Micromanufacturing – From Surface Structuring to
Metamaterials”, Erlangen (Germany), January 10-11, 2011.
29. T. Ergin, N. Stenger, J.C. Halimeh, and M. Wegener, 3D invisibility cloaks at optical frequencies,
International Conference Photonics West, San Francisco (U.S.A.), January 22-27, 2011.
30. M. Wegener, 3D Photonic Metamaterials and Invisibility Cloaks: The Making Of, Invited Plenary
Keynote Talk, The 24th International Conference on Micro Electro Mechanical Systems (MEMS 2011),
Cancun (Mexico), January 23-27, 2011.
31. M. Wegener, Photonic Metamaterials and Transformation Optics: Recent Progress, Spring-Meeting of
the German Physical Society (DPG), Dresden (Germany), March 13-18, 2011.
32. M. Wegener, 3D Photonic Metamaterials and Transformation Optics, Invited Plenary Talk,
International Conference on Nanophotonics (ICNP), Shanghai (China), May 22-26, 2011.
33. M. Wegener, International Symposium on Wave Propagation: From Electrons to Photonic Crystals and
Metamaterials, Crete, Greece, June 8-11, 2011.
34. M. Wegener, Photonic Metamaterials: Optics Starts Walking on Two Feet, International Summer School
on Nano-optics: plasmonics, photonic crystals, metamaterials, and sub-wavelength resolution,
Advanced Study Institute, Ettore Majorana Centre, Erice (Italy), June 30 - July 15, 2011.
35. M. Wegener, Photonic Metamaterials and Transformation Optics, Invited Plenary Talk, International
Conference on Fundamental Optical Processes in Semiconductors (FOPS 2011), Lake Junaluska, North
Carolina (U.S.A.), August 1-5, 2011.
36. S. Linden, F.B.P. Niesler, and M. Wegener, Nonlinear spectroscopy on photonic metamaterials,
Metamaterials: Fundamentals and Applications IV, SPIE 2011 Optics and Photonics Meeting, San Diego
(U.S.A.), August 21-25, 2011.
37. T. Ergin, J. Fischer, J. Halimeh, N. Stenger, and M. Wegener, 3D invisibility cloaks at visible
wavelengths, Metamaterials: Fundamentals and Applications IV, SPIE 2011 Optics and Photonics
Meeting, San Diego (U.S.A.), August 21-25, 2011.
38. E. Ozbay, “Metamaterial Based Enhanced Transmission from Deep Subwavelength Apertures”, 3rd
Mediterranean Conference on Nano-Photonics MediNano-3, Belgrade, Serbia, October 18-19, 2010.
39. E. Ozbay, “Metamaterial Based Enhanced Transmission from Deep Subwavelength Apertures,” 9th
Photonics and Electromagnetic Crystals Conference (PECS-9), Granada, SPAIN, September 27-29 2010.
40. E. Ozbay, “The Magical World of Optical Metamaterials”, Metamaterials Congress 2010, Karlsruhe,
GERMANY, September 13-16, 2010.
41. E. Ozbay, “Photonic Metamaterials: Science Meets Magic”, 6th Nanoscience and Nanotechnology
Conference, Izmir, TURKEY, June 15-18, 2010. (Plenary Talk)
PHOME 213390
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42. E. Ozbay, International Workshop on Photonic and Electromagnetic Crystal Structures, (PECS-IX),
Granada, Spain, September 26-30, 2010.
43. E. Ozbay, “Metamaterial Based Enhanced Transmission from Deep Subwavelength Apertures,” The 3rd
European Topical Meeting on Nanophotonics and Metamaterials, NanoMeta-2011, Seefeld, Tirol,
Austria, January 3-6, 2011.
44. E. Ozbay, “The Magical World of Optical Metamaterials”, SPIE Photonic West 2011, San Francisco,
USA, January 23-27, 2011.
45. E. Ozbay, “Science Meets Magic: Photonic Metamaterials”, SPIE Photonics Europe 2011,
“Metamaterials” Prague, Czech Republic, April 18-21, 2011.
46. E. Ozbay, International Symposium on Wave Propagation: From Electrons to Photonic Crystals and
Metamaterials, Crete, Greece, June 8-11, 2011.
47. J. B. Pendry, The 4th Yamada Symposium on. APSE 2010. Advanced Photons and Science Evolution
2010, Osaka Japan, June 14-18, 2010.
48. J. B. Pendry, Ninth European Summer Campus on the theme "Metamaterials," Strasbourg, France, June
27 - July 5, 2010.
49. J. B. Pendry, International Workshop on Photonic and Electromagnetic Crystal Structures, (PECS-IX),
Granada, Spain, September 26-30, 2010..
50. J. B. Pendry, New Approaches to Biochemical Sensing with Plasmonic Nanobiophotonics, Donostia
International Physics Center in San Sebastian, Sept. 27- Oct. 1, 2010.
51. J. B. Pendry, Multistage modeling workshop, Erlangen, Germany, October 12, 2010.
52. J. B. Pendry, FOM conference, Veldhoven, The Netherlands, January 18-19, 2011. (Plenary Talk)
53. J. B. Pendry, NAVAIR Nano/Meta Materials Workshop for Naval Aviation Applications, Virginia,
USA, February 2-3, 2011.
54. J. B. Pendry, Bringing together Nanoscience & Nanotechnology, Bilbao, Spain, April 11-14, 2011.
(Plenary Talk)
55. J. B. Pendry, Recent Developments in Wave Physics of Complex Media, Cargese, Corsica, France, May
2-7, 2011.
56. J. B. Pendry, The European Future Technologies Conference and Exhibition 2011, Budapest, Hungary,
May 4-6, 2011. (Plenary Talk)
57. J. B. Pendry, Annual international conference "Days of Diffraction" (Metamaterials Workshop), St.
Petersburg, Russia, May 30 - June 3, 2011.
58. J. B. Pendry, International Symposium on Wave Propagation: From Electrons to Photonic Crystals and
Metamaterials, Crete, Greece, June 8-11, 2011.
59. J. B. Pendry, 7th joint U.S./Australia/Canada/UK Workshop on Defense Applications of Signal
Processing (DASP), , Coolum, Queensland, Australia, July 10-14, 2011.
60. J. B. Pendry, SPIE Optics and Photonics, San Diego, Ca, USA, August 21-25, 2011.
Talks/Seminars
M. Wegener
Martin Wegener, Photonische Metamaterialien, Physics Colloquium Universität Paderborn, June 24, 2010
Martin Wegener, Metamaterialien und Transformationsoptik, “Physik am Samstag“, Karlsruhe Institute of
Technology (KIT), July 10, 2010
Martin Wegener, 3D Metamaterials and Transformation Optics, Annual Meeting of the International Max
Planck Research School (IMPRS) Erlangen, Gößweinstein, Oktober 4-8, 2010
Martin Wegener, Metamaterialien und Transformationsoptik, Physics Colloquium Universität Osnabrück,
November 11, 2010
Martin Wegener, Metamaterials and Transformation Optics, Optics Seminar University Twente (The
Netherlands), November 25, 2010
PHOME 213390
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Martin Wegener, Metamaterialien und Transformationsoptik, j-DPG “Meet your Prof“, Karlsruhe, January
17, 2011
Martin Wegener, Photonic Metamaterials: Quo Vadis?, Final Colloquium of the DFG-Forschergruppe
“Light Confinement and Control with Structured Dielectrics and Metals”, Bad Honnef, April 8, 2011
Martin Wegener, Das CFN, Visit of the ROTARY-Club “Karlsruhe Albtal“ at CFN, Karlsruhe, July 28,
2011
J. B. Pendry
14 September 2010 - Lecture at UNESCO Niels Bohr Gold Medal ceremony, Copenhagen
23 September 2010 Resnick lecture Johns Hopkins university Baltimore
1 October 2010 Public lecture, San Sebastian, Spain
28 October 2010 Lecture to Oxford University physics students society
4 November 2010 Public lecture San Diego, USA
17 November 2010 Public lecture, Hong Kong
17 January 2011 Master class FOM meeting, Veldhoven, The Netherlands
1 March 2011, Solvay colloquium, Brussels, Belgium
11 March 2011, Colloquium, Helsinki, Finland
28 March 2011, Distinguished lecture, HKUST, Hong Kong
1 July 2011 Invited talk, A* Singapore Research Center, Singapore
5/6 July 2011 2 Lectures to the Harry Messel summer school, Sydney, Australia
M. Kafesaki
FORTH - Institute of Chemical Engineering and High Temperature Chemical Processes, Patras, Greece,
November 2010.
C. M. Soukoulis
Solvay Colloquium, Brussels, Belgium, May 2011
PHOME 213390
Page 19
3. Deliverables and milestones tables
Deliverables (excluding the periodic and final reports)
TABLE 1. DELIVERABLES5
Del.
no.
Deliverable name
WP
no.
Lead
beneficiar
y
Natur
e
Dissemination
level
Delivery date
from Annex I
(proj. month)
Delivered
Yes/No
Actual / Forecast
delivery date
D11
Assessment of the
existence of IR and
optical PMMs
WP2WP3
KIT-U
R
CO, PU
36
Yes
Sept. 15, 2011
D12
Fabrication issues and
optical characterization of
bulk PMMs
WP2WP3
KIT-U
R
CO, PU
36
Yes
Sept. 15, 2011
D13
Final plan for
dissemination and use of
foreground
WP4
BILKENT
R
CO, PU
36
Yes
Sept. 15, 2011
D14
Progress Report (3rd year)
WP1WP4
FORTH
R
CO, PU
36
Yes
Sept. 15, 2011
D15
Report on awareness and
wider societal implication
WP4
IMPERIA
L
R
CO, PU
36
Yes
Sept. 15, 2011
D16
Conference sessions on
PMMs
WP4
FORTH
R
CO, PU
36
Yes
Sept. 15, 2011
D17
Progress report (Final
report)
WP1WP5
FORTH
R
CO, PU
36
Yes
Sept. 15, 2011
Accomplishment of the deliverables
D11: Assessment of the existence of IR and optical PMMs
See the separate report on D11 (also in Appendix A)
D12: Fabrication issues and optical characterization of bulk PMMs
See the separate report on D12 (also in Appendix A)
D13: Final plan for dissemination and use of foreground
See the separate report on D13
D15: Report on awareness and wider societal implication
See the separate report on D15 (also in Appendix A)
D16: Conference sessions on PMMs
See the separate report on D16 (also in Appendix A)
5
For Security Projects the template for the deliverables list in Annex A1 has to be used.
PHOME 213390
Page 20
4. Project management
Dissemination
Below we mention some steps towards dissemination and use of the PHOME results. (A
publication list and a list of conference presentations has been already reported in WP4
achievements).
 We have created a web page where we have put our articles on PMMs. This page is linked
to the CORDIS sites.
 We present and we will continue to present the PHOME results through publications,
colloquia, and participations to conferences and workshops.
 We have organized sessions devoted to PMMs at international conferences (SPIE 2010, San
Diego, USA, August 2010; Metamaterials Congress Conference, Karlsruhe, Germany
September 2010; International Workshop on Photonic and Electromagnetic Crystal
Structures, (PECS-IX), Granada, Spain, September 2010; Medi-Nano 3, Belgrade, Serbia,
October 2010; 3nd International Workshop on Theoretical and Computational
Nanophotonics (TaCoNa-Photonics), Bad Honnef, Germany, December 2010; The 3rd
European Topical Meeting on Nanophotonics and Metamaterials, NanoMeta-2011, Seefeld,
Tirol, Austria, January 2011; 41st Winter Colloquium on the Physics of Quantum
Electronics (PQE), Snowbird (U.S.A.), January 2011; SPIE Photonics Europe 2011,
“Metamaterials” Prague, Czech Republic, April 2011; International Conference on Materials
for Advanced Technologies (ICMAT 2011), Singapore, June 2011; SPIE 2011, San Diego,
USA, August 2011), where PHOME results will be advertised.
 We have organized a conference on Photonic Metamaterials at Rethymnon, Crete, Greece,
in June 2011. In this conference new results were presented and were discussed what are the
challenges and the future of the photonic metamaterials. See the website
http://cmp.physics.iastate.edu/wavepro/ and all the talks are posted in this site.
 The experimental group of Karlsruhe is in discussion with industries about potential
applications of PMMs as optical isolators.
PHOME 213390
Page 21
5. Explanation of the use of the resources
TABLE 3.1 PERSONNEL, SUBCONTRACTING AND OTHER MAJOR DIRECT COST ITEMS FOR COORDINATOR
(FORTH) FOR THE PERIOD
Work
Item description
Amount
Explanations
Package
1, 2, 3
Personnel costs
130129,86€ Salary supplements for seven senior scientists,
equivalent to 22.20 person months (~89694 €)
Partial salary coverage for three post-docs,
equivalent to 15.32 person months (~31443€)
4
Travel expenses
41615,47 €
2, 3
Consumables
37389,42 €
1,3,4,5
Other
25604,17 €
Salaries for two PhD students for 3,21 person
months each (9000 €)
 Participation of PHOME-related people to the
final
project
conference
(WavePro),
Rethymnon, Crete, June 9-11, 2011 (3409 €).
 Visit of C. Soukoulis in USA
for
collaboration (974 € + 1120 €+907€ +630 €).
 Visit of C. Soukoulis in Athens, for
collaboration with Demokritos Research
center 3093
 Participation of C. Soukoulis & M. Kafesaki
in the 2nd PHOME review meeting in
Karlsruhe (4349)
 Visit of C. Soukoulis in Karlsruhe, for
collaboration with Wegener’s group (838 €)
 Visit of N. Katsarakis in Germany for
collaboration (~1520 €)
 Visit of M. Kafesaki in Belfast for
collaboration with the Metamorphose Virtual
Institute on Metamaterials (1285 €)
 M. Kafesaki’s trip to US, for collaboration
and participation in the SPIE conference on
metamaterials (3583 €)
 M. Kafesaki’s participation in the PIERS
conference in Morocco (1772 €), in “Days of
Diffraction” conference in St. Petersburg
(1696 €), and in MISM conference in
Moscow (2288 €)
 Participation of three people in the ICMAT
conference in Singapore (7734 €)
 Host of visitors for discussion and
collaborations (~4013€)
Photolithography masks, wafers and chemicals for
lithography processes, computer accessories,
small accessories for the THz characterization
equipments, ready microwave metamaterial
samples for testing the main ideas in the
microwaves
Costs for the organization of the WavePro
conference (rooms, meals, stationary) (8874 €)
Renting of room and equipment for the PHOME
final review meeting (349 €)
Payment of support and administration personnel
(for WavePro conference and for general
PHOME 213390
Page 22
support) (11571 €)
Publication costs (1472 €)
Maintenance and repairing
of the FTIR
equipment (1045 €)
Stationary for the organization of the
metamaterials schools (2252 €)
Remaining direct costs
TOTAL DIRECT COSTS6
234738,92
€
TABLE 3.1 PERSONNEL, SUBCONTRACTING AND OTHER MAJOR DIRECT COST ITEMS FOR BENEFICIARY 1
(IMPERIAL) FOR THE PERIOD
Work
Item description
Amount
Explanations
Package
wp1
Personnel costs
€82,834.06
salary of the PDRAs working on this project
Subcontracting
€0.00
wp1/wp4
Major cost item Travel
€2,656.69
travel by Dr Aubry, PDRA, to conferences
relevant to the project
wp1
Major
cost
item €3,341.25
computer software packages for simulation of
Consumables.
data
Remaining direct costs
€0.00
TOTAL DIRECT COSTS7 €88,831.99
TABLE 3.1 PERSONNEL, SUBCONTRACTING AND OTHER MAJOR DIRECT COST ITEMS FOR BILKENT FOR THE
PERIOD
6
7
Work
Package
1, 2, 3
Item description
Amount
Personnel costs
42.287,49 €
2, 3, 4
Travel expenses
25.436,83 €
Explanations
Salaries of 2 postdoctoral researchers (for total 17
months)
 1 graduate student to Int School of Quantum
Electronics, June 2010, Erice-Italy (1.710 €)
 2 graduate students to 4th Int Congress on
Advanced
Electromagnetic
Materials
in
Microwaves and Optics, September 2010,
Karlsruhe-Germany (3.430 €)
 E.Ozbay PHOME project meeting and 4th Int
Congress on Advanced Electromagnetic Materials
in Microwaves and Optics, September 2010,
Karlsruhe-Germany (1.520 €)
 1 graduate student to Lumerical FDTD Solutions
Training, September 2010, London-England (940
€)
 E.Ozbay July 2010 Project Review Meeting,
Karlsruhe-Germany and October 2011 Project
Final Review Meeting Barcelona-Spain (3.900 €)
 2 graduate students to 17th EU PhD School on
Total direct costs have to be coherent with the directs costs claimed in Form C
Total direct costs have to be coherent with the directs costs claimed in Form C
PHOME 213390
Page 23






1, 2, 3
Consumables
46.475,20 €


1, 2, 3
Remaining direct
costs
TOTAL DIRECT COSTS8
Matematerials, December 2010, Crete-Greece
(2.060 €)
E.Ozbay NanoMeta Conference, January 2011,
Seefeld-Austria (1.700 €)
1 graduate student to MRS Meeting, April 2011,
San Fransisco-USA (1.450 €)
1 graduate student to CLEO meeting, May 2011,
Baltimore-USA (2.300 €)
E.Ozbay to WavePro Conference, June 2011,
Crete-Greece (2.300 €)
2 graduate students to TDK UK Office training on
Anechoic Chambers, July 2011, London-England
(1.400 €)
2 graduate students to 18th EU PhD School on
Matematerials, July 2011, Sienna-Italy (2.710 €)
Consumables for the production of various chiral
and composite metamaterial structures which are
made of multiple layers of dielectric-metal
composite structures. These consumables include
PCB manufacturing costs, various substrates,
antennas, FR4, Teflon and Rogers substrates,
electromagnetic absorbers and the micromachining
costs for these metamaterial based structures.
(~25.200 €)
Consumables for micro-nanofabrication of various
photonic metamaterial structures. These include
photoresists, e-beam lithography consumables,
micro-nanofabrication chemicals and substrates.
(~14.800 €), Lumerical FTDT CAD tool for
design of nanostructured metamaterials (~2.550 €),
CST CAD tool for simulation of chiral
metamaterials (~3.850 €)
114.199,52 €
TABLE 3.1 PERSONNEL, SUBCONTRACTING AND OTHER MAJOR DIRECT COST ITEMS FOR PARTNER KIT
FOR THE PERIOD
Work
Package
WP2
WP4
Item description
Personnel costs
Travel expenses
Consumables
Other
Remaining direct costs
TOTAL DIRECT COSTS9
8
9
Amount
97,646.78
3,689.02
Explanations
Salary of 3 researchers for 28 months
Participation T. Ergin, J. Fischer
Conference Cleo Quels, in San Jose, in May 2010
and conference in San Francisco, January 2011
101,335.80
Total direct costs have to be coherent with the directs costs claimed in Form C
Total direct costs have to be coherent with the directs costs claimed in Form C
PHOME 213390
Page 24
6. Appendices
Appendix A: Deliverables
In the next pages the following deliverables have been appended:
Deliverable 11: Assessment of the existence of IR and optical Photonic
Metamaterials
Deliverable 12: Report on fabrication issues and optical characterization of bulk
Photonic Metamaterials
(Deliverable 13: Final plan for dissemination and use of foreground – it will be
submitted as a separate document)
Deliverable 15: Report on awareness and wider societal implications on metamaterials
Deliverable 16: Conference sessions on Photonic Metamaterials
PHOME 213390
Page 25
Deliverable 11: Assessment of the existence of IR and
optical Photonic Metamaterials
Before the beginning of the PHOME project, photonic metamaterials were not actually
“materials” but they were rather planar films composed of planar metamaterial building
blocks. As one makes the step from single functional layers to three-dimensional structures,
the issue of losses becomes more prominent. Suppose that the transmittance of a single
metamaterial layer is as large as 90%. For hundred layers, the resulting transmittance would
be as low as (0.9)100=2.7×10-5 – essentially a completely opaque hence practically useless
structure. Thus, making photonic metamaterials more bulky on the one hand and making them
less lossy on the other hand are two closely related aspects.
Regarding both aspects, the PHOME project has made tremendous progress. The KIT and
FORTH partners have recently jointly published two corresponding reviews on this matter,
one brief perspectives article in Science in December 2010 [D11:1] and one comprehensive
review in Nature Photonics that appeared in August 2011 [D11:2]. Another more popularoriented review has already appeared in Physics Today in October 2010 [D11:3].
Figure D11.1: Overview of three-dimensional photonic metamaterials. Taken from Ref.[D11:2]. Many of these
structures have been realized within PHOME, which has taken a leading role within Europe. Other structures
like the ones in (d)-(g) have been realized by groups in North America.
Figure D11.1 summarizes different three-dimensional architectures taken from one of these
reviews [D11:2]. Stacked double-fishnet negative-index metamaterials operating at telecom
frequencies along the lines of (a) had already been realized by PHOME partners before the
beginning of PHOME. More flexibility arises upon stacking different independent functional
layers made by electron-beam lithography like shown in (b). A variety of corresponding chiral
structures were previously made and jointly published by the KIT and FORTH partners as
reported in PHOME deliverable D10. These results could recently be further improved in a
joint effort between KIT and FORTH by going from twisted crosses [D11:4] towards twisted
split-ring resonator architectures [D11:5]. This structure is in fact closely similar to the one
PHOME 213390
Page 26
shown Fig.D11.1(c). In D10, we also reported on another approach based on threedimensional direct-laser-writing (DLW) optical lithography and gold electroplating shown in
(c). The corresponding gold-helix metamaterial acts as a compact broadband circular polarizer
and represents an early real-world application of the far-reaching ideas of photonic
metamaterials. In D12 we will report on our corresponding PHOME progress with respect to
further moving the operating frequencies of three-dimensional metamaterial structures from
the infrared towards the visible spectral range by introducing stimulated-emission-depletion
(STED) DLW optical lithography.
The KIT partner has also continued along the lines of the circular polarizer, aiming at
systematically further improving its suppression ratio as well as its bandwidth. The latter can,
e.g., by improved by chirping the diameter of the gold helix from the substrate side towards
the top. It is known from antenna theory that the resonance wavelength is basically
proportional to the helix diameter. Thus, adiabatically tapering the helix diameter enables
increasing the bandwidth. However, careful numerical studies were required to find a
compromise between sufficiently slow tapering and reasonable overall helix length
(unpublished). Corresponding metamaterial structures are presently being fabricated and
characterized by KIT. In addition, the circular-polarizer suppression ratio can be increased by
more than an order of magnitude by going from a single helix in one metamaterial unit cell to
three interwoven helices (compare DNA). Here, the idea is to eliminate the remaining linear
birefringence that results from the axis defined by the end of the metal wire and the center of
the helix. However, realizing corresponding structures requires more advanced STED-DLW
optical lithography (see D12). Such advance might also allow realizing the cubic-symmetry
negative-index metamaterial architecture proposed by the FORTH partner and shown in
Fig.D11.1 (h).
Regarding metamaterial losses, the collaboration between KIT and FORTH has investigated
further the microscopic origin of losses in magnetic metamaterials composed of split-ring
resonators operating at telecom frequencies [D11:6]. By detailed experiments and calculations
varying both the metamaterial lattice constant as well as the angle of incidence in obliqueangle transmittance, it was found that long-range retardation effects can influence the
resonance damping by as much as a factor of three. This means that a considerable fraction of
the losses can be eliminated by design. It also means that the metamaterial acts like one entity.
This aspect avoids undesired breaking up into domains upon introducing optical gain.
Metamaterial losses can also be reduced by as much as 30% by post-processing of structures
made via electron-beam lithography using restructuring by electrochemical means [D11:7].
This work has built upon our earlier PHOME work regarding electromodulation of photonic
metamaterials [D11:7].
Ultimately, however, optical gain needs to be introduced if loss-free operation should be
required. The PHOME approach has been from the start to employ semiconductor optical gain
by bringing a single quantum well in close proximity to the meta-atoms, e.g., to split-ring
resonators. Meanwhile the joint KIT and FORTH work that we reported on in D8 has
appeared [D11:9]. More recently, we could demonstrate in direct experiments that the
coupling between quantum well and split-ring resonators decays on a scale of a mere ten
nanometers (submitted). These results largely benefited from PHOME work on spatially
resolving the electromagnetic fields near meta-atoms by either electron-energy-loss
spectroscopy [D11:10] or phase-sensitive optical near-field microscopy/spectroscopy
[D11:11].
Another interesting avenue is to turn the often undesired metamaterial losses to our
advantage. Indeed, several groups have previously suggested metamaterial perfect absorbers,
PHOME 213390
Page 27
however, without turning the heat generated via optical absorption into an actually useful
electrical signal. To this end, the KIT partner has successfully realized a first integrated
metamaterial bolometer depicted in Fig.D11.2 (unpublished).
Figure D11.2: Electron micrographs (different magnifications increasing from top left to bottom right) of an
operational integrated metamaterial bolometer structure fabricated by electron-beam lithography onto a freestanding 30-nm thin SiN membrane on a silicon substrate (unpublished).
Upon resonant absorption of light in the split-ring-resonator like objects (bottom right in
Fig.D11.2), the connected gold meander is heated, hence changing its Ohmic resistance. This
resistance change is measured in four-point geometry. The conceptual advantage compared to
usual bolometers is that the metamaterial allows for integrating a spectral filter as well as a
polarization filter. Both aspects reduce thermal noise. Along these lines, average powers
below one µW at around 1.5-µm wavelength could be detected by the KIT partner at room
temperature. This design can easily be scaled to other operation wavelengths. In this fashion,
also cameras with built-in spectrometers may become possible. Notably, this bolometer is
entirely metal-based – the SiN membrane merely serves for mechanical stability.
Another interesting application of metamaterials lies in frequency conversion, e.g., in secondharmonic generation. Building on our previous PHOME work, the KIT partner recently
performed second-harmonic-generation spectroscopy on split-ring-resonator arrays for the
first time [D11:12]. These experiments might prove helpful in identifying the microscopic
origin of the metamaterial nonlinearities – which is still not well understood theoretically at
present.
PHOME 213390
Page 28
References D11
[D11:1] C.M. Soukoulis and M. Wegener, Optical Metamaterials: More Bulky and Less
Lossy, Science 330, 1633 (2010)
[D11:2] C.M. Soukoulis and M. Wegener, Past achievements and future challenges in the
development of three-dimensional photonic metamaterials, Nature Photon., in press (2011)
[D11:3] M. Wegener and S. Linden, Shaping Optical Space with Metamaterials,
Physics Today 63, 32 (2010)
[D11:4] M.J. Huttunen, G. Bautista, M. Decker, S. Linden, M. Wegener, and M. Kauranen,
Nonlinear chiral imaging of subwavelength-sized twisted-cross gold nanodimers, Opt. Mater.
Express 1, 46 (2011)
[D11:5] M. Decker, R. Zhao, C.M. Soukoulis, S. Linden, and M. Wegener, Twisted split-ringresonator photonic metamaterial with huge optical activity, Opt. Lett. 35, 1593 (2010)
[D11:6] M. Decker, N. Feth, C.M. Soukoulis, S. Linden, and M. Wegener, Retarded longrange interaction in split-ring-resonator square arrays, Phys. Rev. B 84, 085416 (2011)
[D11:7] M. Ruther, L. Shao, S. Linden, J. Weissmüller, and M. Wegener, Electrochemical
Restructuring of Plasmonic Metamaterials, Appl. Phys. Lett. 98, 013112 (2011)
[D11:8] L. Shao, M. Ruther, S. Linden, S. Essig, K. Busch, J. Weissmüller, and M. Wegener,
Electrochemical Modulation of Photonic Metamaterials, Adv. Mater. 22, 5173 (2010)
[D11:9] N. Meinzer, M. Ruther, S. Linden, C.M. Soukoulis, G. Khitrova, J. Hendrickson, J.D.
Olitzky, H.M. Gibbs, and M. Wegener, Arrays of Ag split-ring resonators coupled to InGaAs
single-quantum-well gain, Opt. Express 18, 24140 (2010)
[D11:10] G. Boudarham, N. Feth, V. Myroshnychenko, S. Linden, O. Stephan, C. Colliex, J.
Garcia de Abajo, M. Wegener, and M. Kociak, Spectral Imaging of Individual Split-Ring
Resonators, Phys. Rev. Lett. 105, 255501 (2010)
[D11:11] M. Burresi, D. Diessel, D. van Osten, S. Linden, M. Wegener, and L. Kuipers,
Phase-sensitive near-field optical microscopy on negative-index metamaterials, Nano Lett.
10, 2480 (2010)
[D11:12] F.B.P. Niesler, N. Feth, S. Linden, and M. Wegener, Second-harmonic optical
spectroscopy on split-ring-resonator arrays, Opt. Lett. 36, 1533 (2011)
PHOME 213390
Page 29
Deliverable 12: Report on fabrication issues and optical
characterization of bulk Photonic Metamaterials
The strategy of PHOME towards achieving truly three-dimensional (and bulk) photonic
metamaterials has been to follow two fabrication routes in parallel, namely, planar electronbeam lithography plus stacking of several layers on the one hand (KIT and Bilkent) and
inherently three-dimensional direct-laser-writing (DLW) optical lithography on the other hand
(KIT). The previous status has been reported on in D10, which shall not be repeated here.
Meanwhile it has become clear that the DLW approach – which seemed like the more risky
one at the start – is actually advantageous in terms of fabrication complex structures within
reasonable time.
However, a major drawback of DLW optical lithography has been its limited spatial
resolution, which has not been anywhere near that of state-of-the-art electron-beam
lithography. This aspect has limited further progress by the FORTH and KIT partners
regarding three-dimensional chiral metamaterials as well as further progress with respect to
three-dimensional transformation-optics architectures (e.g., invisibility cloaks) that the
collaboration between KIT and Imperial introduced in a publication in Science magazine in
early 2010. This contrasted the theoretical progress made in PHOME [D12:1] [D12:2]
[D12:3].
Thus, the KIT partner has put tremendous effort on systematically improving the spatial
resolution of DLW optical lithography in all three dimensions by combining [D12:5] [D12:6]
it with the concept of stimulated-emission-depletion (STED) known from fluorescence
microscopy. The underlying idea is illustrated in Fig.D12.1.
Figure D12.1: (a) Scheme of stimulated-emission-depletion (STED) direct-laser-writing (LW) optical
lithography. A red laser focus exposes the photoresist, while a green laser depletes (or de-excites or “erases”)
from all sides using a bottle beam. (b) Foci measured by scanning a gold bead through the focus in three
dimensions. Taken from Ref.[D12:5].
Using this approach, we were able to miniaturize our 2010 result by more than a factor of two
in all three spatial directions. This step has brought the operation frequency from the infrared
all the way to the visible part of the electromagnetic spectrum. In particular, optical
microscopy revealed excellent cloaking in three dimensions and for any polarization of light
at 700-nm wavelength [D12:4]. In this publication, we also systematically studied the
wavelength dependence. Only at wavelengths below 600 nm does the light field “feel” the
PHOME 213390
Page 30
underlying periodicity of the metamaterial. Hence, deviations from the effective-medium
approximation occur. Comparison of the experiments by the KIT partner with ray-tracing
modelling along the lines of Ref.[D12:1] revealed only minor imperfections with respect to
the carpet-cloak design introduced by the Imperial partner in 2008.
Figure D12.2: Scheme of the imaging Michelson interferometer allowing for directly measuring the phase front
reconstruction by a carpet invisibility cloak. Taken from Ref.[D12:8].
In a broad sense, invisibility cloaking based on photonic metamaterials can be viewed as a
particularly demanding example of aberration corrections, which are of interest in many
optical systems. Here, however, not only correction of the light amplitude but also of the
phase of the light wave is mandatory. While the two are connected by the Maxwell equations,
not a single far-field optical experiment had previously actually shown that such invisibility
cloaks also properly reconstruct the phase of the wave. To test this aspect, the KIT partner
has built a dedicated imaging interferometer for detailed optical characterization (see
Fig.D12.2).
Using this refined characterization set-up, the phase images shown in Fig.D12.3 have been
obtained. Obviously, the bump at the top (compare T. Ergin et al., Science 328, 337 (2010))
shows up as a phase hill for the reference. The phase distortion almost completely vanishes
for the case of the cloaking structure shown at the bottom.
The same three-dimensional STED-DLW lithography shall also allow for further
miniaturizing and improving our previously introduced gold-helix photonic metamaterials that
act as broadband circular polarizers. The corresponding status is reported in D11. However,
STED-DLW optical lithography is presently restricted to negative-tone photoresist, whereas
electroplating for gold helices required a positive-tone photoresist. Thus, an additional
inversion step is necessary. We are pursuing atomic-layer deposition of a sacrificial dielectric
before electroplating with gold. Encouraging progress has recently been made by the KIT
partner. The same technology can also be applied to fabricate the corrugated-wire
metamaterials theoretically introduced by the FORTH partner to achieve bulk threedimensional negative-index metamaterials with improved angular dependence.
Another promising route is to replace the traditional metals (e.g., gold or silver) by very
highly doped semiconductors. This was, e.g., recently suggested by Alexandra Boltasseva and
Harry Atwater (Science 331, 290 (2011)) for planar metamaterial structures. In PHOME, the
KIT partner has successfully fabricated [D12:7] three-dimensional architectures based on Aldoped ZnO grown by atomic-layer deposition. Plasma frequencies up to visible frequencies
PHOME 213390
Page 31
have been achieved at reasonably small losses [D12:7]. Thus, this approach appears to be very
attractive for three-dimensional infrared metamaterials and transformation-optics
architectures.
Figure D12.3: Measured phase images (compare Fig.D12.2) on carpet-cloak photonic metamaterial structures
made by STED-DLW optical lithography and measured at 700-nm wavelength of light. Taken from Ref.[D12:8].
The other novel path in facing losses is based on a combination of electromagneticallyinduced transparency (EIT) with non-linearity and gain components. EIT in metamaterials is
based on two elements—the active and the dark; one of the elements, according to our
proposed design, incorporates the gain component and transfers the energy non-linearly to the
other element. Under certain conditions, the spectral response of such a coupled structure can
be significantly different from the mere superposition of the two independent resonances.
Recently, we have fabricated two EIT structures [D12:9, D12:10] that showed low absorption
and slow light velocity. Figure D12.4 shows the photograph of the sample and the schematic
representation of our structure [D12:9].
Fig. D12.4. (a) Photograph of the sample. (b) Schematic
representation of our structure. Ref. [D12:9].
Fig. D12.5. All spectra exhibit the typical features of EIT- with
low absorption inside a broader resonance. Ref. [D12:9].
Therefore, the absorption spectrum develops a very narrow transmission window in the
broader Lorentzian-like absorption peak associated with the transition to the excited state (see
Fig. D12.4).
Slow Light: Another application of the EIT is to slow the light by a large factor. At the
resonance frequency, the anomalous dispersion profile, normally observed for a two-level
PHOME 213390
Page 32
resonance, is transformed into an extremely steep normal dispersion. This may slow down
light pulses by many orders of magnitude [D12:10]. Most of the EIT experimental work has
not seen a strong absorption dip, and the reduction of the speed of light is very small—a
factor of five to ten. So there is a strong need to experimentally demonstrate that
metamaterials can reduce the speed of light dramatically. We have collaborated with Prof.
Steven Anlage’s group, from the Univ. of Maryland, which has expertise in fabricating
superconducting wires. We have fabricated [D12:10] these EIT structures with metals and
superconductors, to verify that the experimental results will agree with our numerical
simulations and reduce the speed of light by a factor of 500. Therefore, we will have a strong
reduction in the speed of light and these new samples will be useful to construct light-slowing
devices. In addition, by manipulation of the superconducting properties of the dark
resonators through temperature or magnetic field, the EIT effects are tunable to an
unprecedented extent [D12:10].
References D12
[D12:1] T. Ergin, J.C. Halimeh, N. Stenger, and M. Wegener, Optical microscopy of 3D
carpet cloaks: ray-tracing simulations, Opt. Express 18, 20535 (2010)
[D12:2] R. Schmied, J.C. Halimeh, and M. Wegener, Conformal carpet and grating cloaks,
Opt. Express 18, 24361 (2010)
[D12:3] J.C. Halimeh, R. Schmied, and M. Wegener, Newtonian photorealistic ray tracing of
grating cloaks and correlation-function-based cloaking-quality assessment, Opt. Express 19,
6078 (2011)
[D12:4] J. Fischer, T. Ergin, and M. Wegener, Three-dimensional polarization-independent
visible-frequency carpet invisibility cloak, Opt. Lett. 36, 2059 (2011)
[D12:5] J. Fischer and M. Wegener, Three-dimensional direct laser writing inspired by
stimulated-emission-depletion microscopy, Opt. Mater. Express 1, 614 (2011)
[D12:6] T.J.A. Wolf, J. Fischer, M. Wegener, and A.-N. Unterreiner, Pump-probe
spectroscopy on photoinitiators for stimulated-emission-depletion optical lithography,
Opt. Lett., in press (2011)
[D12:7] A. Frölich and M. Wegener, Spectroscopic characterization of highly doped ZnO by
atomic-layer
deposition
for
three-dimensional
infrared
metamaterials,
Opt. Mater. Express, in press (2011)
[D12:8] T. Ergin, J. Fischer, and M. Wegener, Optical phase cloaking of 700-nm light waves
in the far field by a three-dimensional carpet cloak, submitted (2011); arXiv:1107.4288v1
[D12:9] R. Zhao, Lei Zhang, J. Zhou, Th. Koschny and C. M. Soukoulis, “Conjugated
gammadion chiral metamaterials with optical activity and negative refractive index,” Phys.
Rev B 83, 035105 (2011).
[D12:10] C. Kurter, P. Tassin, Lei Zhang, Th. Koschny, A. P. Zhuravel, A. V. Ustinov, S. M.
Anlage and C. M. Soukoulis, “Classical analogue of Electromagnetic Induced Transparency
with a metal/superconductor hybrid metamaterial,” Phys. Rev. Lett. 107, 043901 (2011).
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Deliverable 15: Report on awareness and wider societal
implications on metamaterials
Optics in particular and electromagnetic radiation in general pervades every aspect of our
lives. We only have to think of mobile phones, optical fibers for telecoms, MRI, optical
microscopy, GPS, satellite communications, laser surgery, THz imaging for security, keyhole
surgery enabled by endoscopes: the list is endless. Yet whenever an application comes to be
realized we have to ask what materials will be used to manufacture the device and therein lays
a problem. Electromagnetic theory allows a wide range of material properties and indeed
requires many of these properties to achieve some of the more exotic applications. However
nature has not been so generous and many useful properties are missing from the list of
naturally available materials.
So it is that metamaterials have come to be such an important and well-studied field. The
concept is very simple: a material’s properties can be changed not only by altering the
chemistry of its constituents but also by altering its microscopy structure, structure on a scale
much less than the wavelength. A good example with which we are familiar is silver. As a flat
highly polished surface silver makes an excellent mirror. On the other hand very finely
divided silver nanoparticles that are to be found in a black and white photographic negative
absorb light and are black in appearance. This powerful concept can generate astonishing
material properties such as negative refraction and chirality far more strong than found in any
naturally occurring material. The concept is relatively simple to apply for RF applications
because the wavelength is relatively large and the sub wavelength structures of the
metamaterial are of easily manufactured dimensions. Greater challenges appear when pushing
the concept into the THz, IR and visible regions of the spectrum where, arguable the greater
societal rewards are to be found. In this respect the Karlsruhe partner is perfecting the
technology for optical metamaterials where the length scales of the structures are on the
nanoscale. At the same time the FORTH partner using computational techniques has been
probing other limits to visible frequency metamaterials. Even metamaterials have to be
manufactured from naturally occurring substances and ultimately their properties will limit
what can be achieved with metamaterials. In particular the responsiveness of electrons at
higher frequencies becomes sluggish leading to absorption of incident radiation. Conquering
these limitations with clever designs was required to extend the applicability of metamaterials.
Not only do scientists find the new concepts stimulating, but also they have such a simple but
powerful idea behind them that a popular audience can easily grasp their significance. Several
of the team has spent much time giving popular lectures to general audiences, including
outreaching to schoolchildren. Over the course of the project of the order of 100 lectures will
have been delivered by members of the team provoking interest in and appreciated of not just
our particular area of research but of the social significance of science in general.
An exciting field such as metamaterials often leads to strong debate. This is of course the stuff
of scientific progress: identifying challenges and debating the way forward until an agreed
solution is found. These debates often attract the attention of the press both for the scientific
issues themselves, of course, but also for the interplay of personalities. This exposure to the
general public of scientists as people who sometimes collaborate, sometimes disagree,
sometimes quarrel, adds a human dimension to the public perception of science that is all to
often missing from the reporting of science. Members of the PHOME team have been
prominent in the many debates that have taken place and been reported. For example the work
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of the Karlsruhe group was reported in The New York Times: “Strides in Materials, but No
Invisibility Cloak”, November 9th, 2010 and in The International Herald Tribune: “Dreaming
Up Uses for a Giant Invisibility Machine”, November 29th, 2010. The work of the FORTH
group was reported in many Greek newspapers, like Kathimerini, Eleftherotypia, Enthos and
Patris.
In another recent instance, Pendry, Imperial College, delivered a series of lectures in Sydney
Australia to the Harry Messel School. Exceptionally bright school children from all over the
world are invited to Sydney to participate in 2 weeks of science. During their stay they are
presented with a book containing write ups of the lectures that they hear, an enduring
memento of their experiences.
The book of lectures for the 36th Professor Harry Messel International School 2011, “Light
and Matter”, is available from their web site at:
http://www.physics.usyd.edu.au/foundation.old/index_iss.html
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Deliverable 16: Conference sessions on Photonic
Metamaterials
In this Deliverable we list the conferences and schools where sessions on photonic
metamaterials have been organized (or co-organized) by members of the PHOME project, or
where members of PHOME participated in the organizing and program committee.
Conferences chaired or co-chaired by PHOME people with sessions on photonic
metamaterials
1. XXIV Panhellenic Conference of Solid State Physics and Materials Science, Heraklion,
Crete, Greece, September 2008
2. 1st Mediterranean conference on Nanophotonics (Medi-Nano 1), Istanbul, Turkey,
October 2008
3. OSA Topical Meeting Plasmonics and Metamaterials (META), Rochester ,USA, Oct
2008
4. Heraeus Workshop Periodic Nanostructures for Photonics, Bad Honnef, Germany, 2008
5. International conference on Electrical, Transport and Optical Properties of
Inhomogeneous Media (ETOPIM 8), Rethymnon, Crete, Greece, June 2009
6. 2nd Mediterranean conference on Nanophotonics (Medi-Nano 2), Athens, Greece, October
2009
7. The 2nd European Topical Meeting on Nanophotonics and Metamaterials, (NanoMeta),
Seefeld, Tirol, Austria, January 2009
8. Metamaterials 2010 Conference, Karlsruhe, Germany, September 2010
9. OSA Photonic Metamaterials and Plasmonics (META), Tuscon, USA, June 2010
10. SPIE Photonics Europe, Brussels, April 2010
11. Wave Propagation: from electrons to photonic crystals and metamaterials (WavePro),
Rethymnon, Crete, Greece, June 2011 (conference organized and supported by PHOME),
http://cmp.physics.iastate.edu/wavepro/
Schools related to photonic metamaterials organized by PHOME people
1. School on Fabrication and Optical Properties of Nanostructured Metamaterials,
Rethymnon, Crete, Greece (June 12-13, 2009).
2. European School on Experimental Characterization of Electromagnetic Metamaterials,
Heraklion (FORTH), Crete, Greece (December 13-17, 2010)
3. Summer School Bringing Gain to Metamaterials, Karlsruhe, Germany (2010)
4. CFN summer school Nano-Photonics, Bad Herrenalb, Germany, 2010
Conferences where PHOME people participated in the organizing committee and the
program committee or organized sessions on photonic metamaterials
1. The first International Workshop on Theoretical and Computational Nanophotonics
(TaCoNa-Photonics), Bad Honnef, December 2008
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2. International Conference on “Quantum Electronics and Laser Science (QELS)”, San
Francisco, USA, 2008
3. SPIE Europe, Photonics Europe 2008, Strasbourg, France, 2008
4. Photonic and Electromagnetic Crystal Structures (PECS), Sydney, Australia, April 2009
5. SPIE Optics and Photonics, San Diego, USA, August 2009
6. 2nd International Workshop on Theoretical and Computational Nanophotonics (TaCoNaPhotonics), Bad Honnef, Germany, December 2009
7. MRS Fall Meeting, Boston, USA, December 2009
8. 40th Winter Colloquium of Quantum Electronics, Snowbird, USA, January 2010
9. META’10, Cairo, Egypt, February 2010
10. International Quantum Electronics Conference (IQEC), Baltimore, USA, 2010
11. SPIE Optics and Optoelectronics, Prague, Czech Republic, 2010
12. SPIE 2010, San Diego, USA, August 2010
13. Photonic and Electromagnetic Crystal Structures, (PECS-IX), Granada, Spain, September
2010
14. 3rd Mediterranean conference on Nanophotonics (Medi-Nano 3), Belgrade, Serbia,
October 2010
15. 3nd International Workshop on Theoretical and Computational Nanophotonics (TaCoNaPhotonics), Bad Honnef, Germany, December 2010
16. The 3rd European Topical Meeting on Nanophotonics and Metamaterials, NanoMeta2011, Seefeld, Tirol, Austria, January 2011
17. 41st Winter Colloquium on the Physics of Quantum Electronics (PQE), Snowbird, USA,
January 2011
18. SPIE Photonics Europe 2011, Prague, Czech Republic, April 2011
19. International Conference on Materials for Advanced Technologies (ICMAT 2011),
Singapore, June 2011
20. CLEO: Science (formerly QELS), Baltimore, USA, 2011
21. SPIE Optics and Photonics 2011, San Diego, USA, August 2011